In 1926 helped the Amundsen-Ellsworth-Nobile Expedition prepare to fly the dirigible Norge over the North Pole.
Chief pilot of the Byrd Antarctic Expedition in 1929, he navigated a Ford tri-motor over the South Pole.
Served as technical advisor for Amelia Earhart for her successful flight across the Atlantic.
From 1933-35 served as chief pilot of the Lincoln-Ellsworth trans-Antarctic expedition.
Assisted the U.S. Air Force in building a base in Greenland and served the Air Force as an expert Arctic aviator.
Conducted dangerous resupply operations over Norway in 1944 and completed the first daylight resupply missions into Norway in the war and the longest transport flights in the European Theater of Operations.
Helped organize the Scandinavian Airlines System.
First pilot to fly an airplane over both Poles for which he was awarded the Harmon Trophy.